package org.apache.ibatis.reflection;

import org.apache.ibatis.reflection.invoker.GetFieldInvoker;
import org.apache.ibatis.reflection.invoker.Invoker;
import org.apache.ibatis.reflection.invoker.MethodInvoker;
import org.apache.ibatis.reflection.invoker.SetFieldInvoker;
import org.apache.ibatis.reflection.property.PropertyNamer;

import com.barney.support.util.StringUtils;

import java.lang.reflect.*;
import java.util.*;

/**
 * This class represents a cached set of class definition information that
 * allows for easy mapping between property names and getter/setter methods.
 *
 * MyBatis에서 DB 컬럼명을 Java의 camelCase로 자동으로 매핑시켜주기 위하여 수정되었다.
 * 소스 상에서는 <code>MODIFIED</code>를 찾아보면 무엇이 변경되었는지 알 수 있다.
 * @see http://groups.google.com/group/mybatis-user/msg/7ea4b4ba34243808
 * @see StringUtils
 */
@SuppressWarnings("rawtypes")
public class Reflector {

	private static boolean classCacheEnabled = true;
	private static final String[] EMPTY_STRING_ARRAY = new String[0];
	private static final Map<Class, Reflector> REFLECTOR_MAP = Collections.synchronizedMap(new HashMap<Class, Reflector>());

	private Class type;
	private String[] readablePropertyNames = EMPTY_STRING_ARRAY;
	private String[] writeablePropertyNames = EMPTY_STRING_ARRAY;
	private Map<String, Invoker> setMethods = new HashMap<String, Invoker>();
	private Map<String, Invoker> getMethods = new HashMap<String, Invoker>();
	private Map<String, Class> setTypes = new HashMap<String, Class>();
	private Map<String, Class> getTypes = new HashMap<String, Class>();
	private Constructor defaultConstructor;

	private Map<String, String> caseInsensitivePropertyMap = new HashMap<String, String>();

	// MODIFIED
	private Map<String, String> propertyMap = new HashMap<String,String>();

	private Reflector(Class clazz) {
		System.err.println("MODIFIED MyBatis Reflector");
		type = clazz;
		addDefaultConstructor(clazz);
		addGetMethods(clazz);
		addSetMethods(clazz);
		addFields(clazz);
		readablePropertyNames = getMethods.keySet().toArray(new String[getMethods.keySet().size()]);
		writeablePropertyNames = setMethods.keySet().toArray(new String[setMethods.keySet().size()]);

		// MODIFIED
		putAll(readablePropertyNames);
		putAll(writeablePropertyNames);
		/* MODIFIED
		for (String propName : readablePropertyNames) {
			caseInsensitivePropertyMap.put(propName.toUpperCase(Locale.ENGLISH), propName);
		}
		for (String propName : writeablePropertyNames) {
			caseInsensitivePropertyMap.put(propName.toUpperCase(Locale.ENGLISH), propName);
		}
		*/
	}

	// MODIFIED
	private void putAll(String[] propertyNames) {
		for (String propName : propertyNames) {
			caseInsensitivePropertyMap.put(propName.toUpperCase(Locale.ENGLISH), propName);
			caseInsensitivePropertyMap.put(StringUtils.camelCase2underScore(propName).toUpperCase(), propName);
		}
	}

	private void addDefaultConstructor(Class clazz) {
		Constructor[] consts = clazz.getDeclaredConstructors();
		for (Constructor constructor : consts) {
			if (constructor.getParameterTypes().length == 0) {
				if (canAccessPrivateMethods()) {
					try {
						constructor.setAccessible(true);
					} catch (Exception e) {
						// Ignored. This is only a final precaution, nothing we can do.
					}
				}
				if (constructor.isAccessible()) {
					this.defaultConstructor = constructor;
				}
			}
		}
	}

	private void addGetMethods(Class cls) {
		Method[] methods = getClassMethods(cls);
		for (Method method : methods) {
		String name = method.getName();
		if (name.startsWith("get") && name.length() > 3) {
			if (method.getParameterTypes().length == 0) {
				name = PropertyNamer.methodToProperty(name);
				addGetMethod(name, method);
			}
		} else if (name.startsWith("is") && name.length() > 2) {
			if (method.getParameterTypes().length == 0) {
				name = PropertyNamer.methodToProperty(name);
				addGetMethod(name, method);
			}
		}
		}
	}

	private void addGetMethod(String name, Method method) {
		if (isValidPropertyName(name)) {
			getMethods.put(name, new MethodInvoker(method));
			getTypes.put(name, method.getReturnType());
		}
	}

	private void addSetMethods(Class cls) {
		Map<String, List<Method>> conflictingSetters = new HashMap<String, List<Method>>();
		Method[] methods = getClassMethods(cls);
		for (Method method : methods) {
			String name = method.getName();
			if (name.startsWith("set") && name.length() > 3) {
				if (method.getParameterTypes().length == 1) {
					name = PropertyNamer.methodToProperty(name);
					addSetterConflict(conflictingSetters, name, method);
				}
			}
		}
		resolveSetterConflicts(conflictingSetters);
	}

	private void addSetterConflict(Map<String, List<Method>> conflictingSetters, String name, Method method) {
		List<Method> list = conflictingSetters.get(name);
		if (list == null) {
		list = new ArrayList<Method>();
		conflictingSetters.put(name, list);
		}
		list.add(method);
	}

	private void resolveSetterConflicts(Map<String, List<Method>> conflictingSetters) {
		for (String propName : conflictingSetters.keySet()) {
			List<Method> setters = conflictingSetters.get(propName);
			Method firstMethod = setters.get(0);
			if (setters.size() == 1) {
				addSetMethod(propName, firstMethod);
			} else {
				Class expectedType = getTypes.get(propName);
				if (expectedType == null) {
					throw new ReflectionException("Illegal overloaded setter method with ambiguous type for property "
						+ propName + " in class " + firstMethod.getDeclaringClass() + ".  This breaks the JavaBeans " +
						"specification and can cause unpredicatble results.");
				} else {
					Iterator<Method> methods = setters.iterator();
					Method setter = null;
					while (methods.hasNext()) {
						Method method = methods.next();
						if (method.getParameterTypes().length == 1
							&& expectedType.equals(method.getParameterTypes()[0])) {
						setter = method;
						break;
						}
					}
					if (setter == null) {
						throw new ReflectionException("Illegal overloaded setter method with ambiguous type for property "
							+ propName + " in class " + firstMethod.getDeclaringClass() + ".  This breaks the JavaBeans " +
							"specification and can cause unpredicatble results.");
					}
					addSetMethod(propName, setter);
				}
			}
		}
	}

	private void addSetMethod(String name, Method method) {
		if (isValidPropertyName(name)) {
		setMethods.put(name, new MethodInvoker(method));
		setTypes.put(name, method.getParameterTypes()[0]);
		}
	}

	private void addFields(Class clazz) {
		Field[] fields = clazz.getDeclaredFields();
		for (Field field : fields) {
		if (canAccessPrivateMethods()) {
			try {
			field.setAccessible(true);
			} catch (Exception e) {
			// Ignored. This is only a final precaution, nothing we can do.
			}
		}
		if (field.isAccessible()) {
			if (!setMethods.containsKey(field.getName())) {
			if (!Modifier.isFinal(field.getModifiers())) {
				addSetField(field);
			}
			}
			if (!getMethods.containsKey(field.getName())) {
			addGetField(field);
			}
		}
		}
		if (clazz.getSuperclass() != null) {
		addFields(clazz.getSuperclass());
		}
	}

	private void addSetField(Field field) {
		if (isValidPropertyName(field.getName())) {
		setMethods.put(field.getName(), new SetFieldInvoker(field));
		setTypes.put(field.getName(), field.getType());
		}
	}

	private void addGetField(Field field) {
		if (isValidPropertyName(field.getName())) {
		getMethods.put(field.getName(), new GetFieldInvoker(field));
		getTypes.put(field.getName(), field.getType());
		}
	}

	private boolean isValidPropertyName(String name) {
		return !(name.startsWith("$") || "serialVersionUID".equals(name) || "class".equals(name));
	}

	/**
	 * This method returns an array containing all methods
	 * declared in this class and any superclass.
	 * We use this method, instead of the simpler Class.getMethods(),
	 * because we want to look for private methods as well.
	 *
	 * @param cls The class
	 * @return An array containing all methods in this class
	 */
	private Method[] getClassMethods(Class cls) {
		HashMap<String, Method> uniqueMethods = new HashMap<String, Method>();
		Class currentClass = cls;
		while (currentClass != null) {
		addUniqueMethods(uniqueMethods, currentClass.getDeclaredMethods());

		// we also need to look for interface methods -
		// because the class may be abstract
		Class[] interfaces = currentClass.getInterfaces();
		for (Class anInterface : interfaces) {
			addUniqueMethods(uniqueMethods, anInterface.getMethods());
		}

		currentClass = currentClass.getSuperclass();
		}

		Collection<Method> methods = uniqueMethods.values();

		return methods.toArray(new Method[methods.size()]);
	}

	private void addUniqueMethods(HashMap<String, Method> uniqueMethods, Method[] methods) {
		for (Method currentMethod : methods) {
		if (!currentMethod.isBridge()) {
			String signature = getSignature(currentMethod);
			// check to see if the method is already known
			// if it is known, then an extended class must have
			// overridden a method
			if (!uniqueMethods.containsKey(signature)) {
			if (canAccessPrivateMethods()) {
				try {
				currentMethod.setAccessible(true);
				} catch (Exception e) {
				// Ignored. This is only a final precaution, nothing we can do.
				}
			}

			uniqueMethods.put(signature, currentMethod);
			}
		}
		}
	}

	private String getSignature(Method method) {
		StringBuffer sb = new StringBuffer();
		sb.append(method.getName());
		Class[] parameters = method.getParameterTypes();
		for (int i = 0; i < parameters.length; i++) {
		if (i == 0) {
			sb.append(':');
		} else {
			sb.append(',');
		}
		sb.append(parameters[i].getName());
		}
		return sb.toString();
	}

	private static boolean canAccessPrivateMethods() {
		try {
		SecurityManager securityManager = System.getSecurityManager();
		if (null != securityManager) {
			securityManager.checkPermission(new ReflectPermission("suppressAccessChecks"));
		}
		} catch (SecurityException e) {
		return false;
		}
		return true;
	}

	/**
	 * Gets the name of the class the instance provides information for
	 *
	 * @return The class name
	 */
	public Class getType() {
		return type;
	}

	public Constructor getDefaultConstructor() {
		if (defaultConstructor != null) {
		return defaultConstructor;
		} else {
		throw new ReflectionException("There is no default constructor for " + type);
		}
	}

	public Invoker getSetInvoker(String propertyName) {
		Invoker method = setMethods.get(propertyName);
		if (method == null) {
		throw new ReflectionException("There is no setter for property named '" + propertyName + "' in '" + type + "'");
		}
		return method;
	}

	public Invoker getGetInvoker(String propertyName) {
		Invoker method = getMethods.get(propertyName);
		if (method == null) {
		throw new ReflectionException("There is no getter for property named '" + propertyName + "' in '" + type + "'");
		}
		return method;
	}

	/**
	 * Gets the type for a property setter
	 *
	 * @param propertyName - the name of the property
	 * @return The Class of the propery setter
	 */
	public Class getSetterType(String propertyName) {
		Class clazz = setTypes.get(propertyName);
		if (clazz == null) {
		throw new ReflectionException("There is no setter for property named '" + propertyName + "' in '" + type + "'");
		}
		return clazz;
	}

	/**
	 * Gets the type for a property getter
	 *
	 * @param propertyName - the name of the property
	 * @return The Class of the propery getter
	 */
	public Class getGetterType(String propertyName) {
		Class clazz = getTypes.get(propertyName);
		if (clazz == null) {
		throw new ReflectionException("There is no getter for property named '" + propertyName + "' in '" + type + "'");
		}
		return clazz;
	}

	/**
	 * Gets an array of the readable properties for an object
	 *
	 * @return The array
	 */
	public String[] getGetablePropertyNames() {
		return readablePropertyNames;
	}

	/**
	 * Gets an array of the writeable properties for an object
	 *
	 * @return The array
	 */
	public String[] getSetablePropertyNames() {
		return writeablePropertyNames;
	}

	/**
	 * Check to see if a class has a writeable property by name
	 *
	 * @param propertyName - the name of the property to check
	 * @return True if the object has a writeable property by the name
	 */
	public boolean hasSetter(String propertyName) {
		return setMethods.keySet().contains(propertyName);
	}

	/**
	 * Check to see if a class has a readable property by name
	 *
	 * @param propertyName - the name of the property to check
	 * @return True if the object has a readable property by the name
	 */
	public boolean hasGetter(String propertyName) {
		return getMethods.keySet().contains(propertyName);
	}

	public String findPropertyName(String name) {
		// MODIFIED
		// return caseInsensitivePropertyMap.get(name.toUpperCase(Locale.ENGLISH));
		String propName = propertyMap.get(name);
		if (propName == null) {
			propName = caseInsensitivePropertyMap.get(name.toUpperCase());
			if (propName != null) {
				propertyMap.put(name, propName);
			}
		}
		return propName;
	}

	/**
	 * Gets an instance of ClassInfo for the specified class.
	 *
	 * @param clazz The class for which to lookup the method cache.
	 * @return The method cache for the class
	 */
	public static Reflector forClass(Class clazz) {
		if (classCacheEnabled) {
		synchronized (clazz) {
			Reflector cached = REFLECTOR_MAP.get(clazz);
			if (cached == null) {
			cached = new Reflector(clazz);
			REFLECTOR_MAP.put(clazz, cached);
			}
			return cached;
		}
		} else {
		return new Reflector(clazz);
		}
	}

	public static void setClassCacheEnabled(boolean classCacheEnabled) {
		Reflector.classCacheEnabled = classCacheEnabled;
	}

	public static boolean isClassCacheEnabled() {
		return classCacheEnabled;
	}

}
